Medicament injectors

ABSTRACT

The specification and drawings disclose two embodiments of medicament injectors of the type commonly referred to as &#39;&#39;&#39;&#39;velocity injectors.&#39;&#39;&#39;&#39; Both embodiments provide means by which the quantity of medicament can be varied. Each embodiment also has a single valve assembly which controls filling, cleaning, and firing. An important aspect of one embodiment is the use of a rotatable multiple dosage supply housing which can be sequentially indexed to bring medicament ampules into proper relationship with the valve assembly. In addition to the features noted above, the second embodiment discloses an injector which automatically injects when pressed against the patient.

United States Patent 1 Yanof et al.

1 Feb. 6, 1973 [54] MEDICAMENT INJECTORS [58] Field of Search 128/173 H, 218 D, 218 DA, 218 A,128/218 PA, 218 R, 218 P, 215, 214 F, 184; 222/144,144.5, 130,389

[56] References Cited UNITED STATES PATENTS 3,057,349 10/1962 lsmach ..128/173 H 3,461,867 8/1969 Zimmet c1211.. ....l28/173 H 3,515,130 6/1970 Tsujino ....128/173 H 9/1953 Smoot ..128/173 H 2,645,223 7/1953 Lawshe et al.... ..128/173 H 3,330,277 7/1967 Gabriels 1 ..128/173 H 2,754,818 7/1956 Schercr ..128/173 H 3,527,212 9/1970 Clark ..128/173 H Primary Examiner-Richard A. Gaudet Assistant Examiner-G. F. Dunne Attorney-Fay, Sharpe & Mulholland [57] ABSTRACT The specification and drawings disclose two embodiments of medicament injectors of the type commonly referred to as velocity injectors." Both embodiments provide means by which the quantity of medicament can be varied. Each embodiment also has a single valve assembly which controls filling, cleaning, and firing. An important aspect of one embodiment is the use of a rotatable multiple dosage supply housing which can be sequentially indexed to bring medicament ampules into proper relationship with the valve assembly. In addition to the features noted above, the second embodiment discloses an injector which automatically injects when pressed against the patient.

22 Claims, 11 Drawing Figures PAIENIEDFEB 6 ma SHEEI 10F 3 BY HOWARD M YANOF jay, 5W 6 mad/20110114 ATTOQL/EK MEDICAMENT INJECTORS The present invention is directed toward the art of hypodermic injectors and, more particularly, to improved injectors of the type by which medicament can be injected without the use of a skin-piercing needle.

The invention will be described with reference to certain preferred embodiments; however, it will be apparent that the invention could be embodied in many specific structural arrangements.

Hypodermic injectors which inject medicament by use of a high velocity jet without a skin-piercing needle are well known and often referred to as velocity injectors. Such velocity injectors are often used in mass innoculations. They have not, however, been widely used for giving individual shots on a limited basis, such as in doctors and dentists offices, or by diabetics in their homes.

The primary reason velocity injectors have been limited to mass innoculation type use has been their general complexity, bulkiness, and high cost. Many attempts have been made to provide a simple, compact, and inexpensive velocity injector. The prior attempts have not been successful for many reasons. Typically, the simpler units have not been capable of providing varying dosages except through the use of medicament ampules in many sizes. For someone like a diabetic whose dosage may change substantially from day-today depending upon exercise and food intake, this would require maintaining a large supply of ampules of differing sizes. Further, the prior inexpensive units have been difficult to clean and somewhat troublesometo load. An additional problem with many of the prior units has been the possibility of insufficient velocity on the medicament. This has been particularly true of those units wherein the actuating pressure is supplied from a compressed gas cartridge which is used for several shots. For example, if there has been a substantial time period between shots, gas leakage can cause reduction in pressure to a level wherein the next shot is not given sufficient velocity. Alternately, in a series of shots, the pressure of the gas cartridge is continually dropping so that the velocity of each shot is less. Consequently, to be safe, it is necessary to change gas cartridges relatively more often than absolutely necessary.

The present invention overcomes the abovediscussed problems and provides a simple and highly reliable velocity injector. Injectors formed in accordance with the invention are highly reliable, compact, and safe to use.

In accordance with one aspect of the invention, there is provided an injector having a first body portion including a medicament receiving chamber and an orifice through which the medicament can be ejected. The chamber includes at least one movable wall portion through which pressure can be applied to medicament in the chamber to cause it to be ejected through the orifice at a velocity sufficient to enter tissues without use of a needle. Connected with the first body portion is a second body portion including housing means for carrying a plurality of medicament ampules and a plurality of cartridges holding a propellant gas under substantial pressure. Passage means including valve means connect between the housing means and the first body portion to controllably supply medicament and pressurizing gas to the chamber on opposite sides of the movable wall. Additionally, indexing means are provided for permitting movement of the housing means relative to the first body to bring selected ones of said ampules and capsules into flow relationship with the passages.

Preferably, but not necessarily, the housing means also includes a container of cleaning solution which can be indexed into alignment with the passage means for flushing at least the medicament receiving chamber. Additionally, the housing means is preferably rotatable relative to the first body portion and provided with means for preventing inadvertent actuation of the cleaning solution. Preferably, but not necessarily, the gas cartridge used with the cleaning solution is under a pressure sufficiently low so that injection cannot take place.

In accordance with a further aspect of the invention, there is provided a velocity injector including a first housing adapted to hold a medicament ampule and propellant gas cartridge. Carried by the housing and movable relative thereto is a second housing including a medicament chamber having a movable wall portion and an outlet orifice through which medicament can be ejected. Means are provided for supplying pressurized gas to a position behind the movable wall portion including a passageway extending through the second housing. Associated with the second housing are means to prevent pressurizing gas from flowing through the passageway except upon movement of the second housing relative to the first housing in a direction toward the outlet orifice.

The arrangement of the housing portions is such that the user merely presses the outlet against the skin causing movement of the second housing relative to the first to thereby release pressurized gas and produce an injection. It is not necessary to consciously press an actuating lever, button, or the like. This is advantageous for persons such as diabetics who must give themselves shots.

The above and other objects and advantages will become apparent from the following description when read in conjunction with the accompanying drawings wherein:

FIG. I is a longitudinal, cross-sectional view through a preferred embodiment of injector formed in accordance with the invention;

FIG. 2 is a cross-sectional view taken on line 22 of FIG. 1;

FIG. 3 is a view taken on line 3-3 of FIG. 1 and showing the actuating knob for valve assembly of the FIG. I embodiment;

FIG. 4 is pictorial view of a typical medicament or pressurizing gas cartridge used in the preferred form of the invention;

FIG. 5 is a pictorial, somewhat schematic, showing of the rotary slide valve assembly used in the FIG. 1 embodiment;

FIGS. 6A and 6B are views taken on line 6-6 of FIG. 5 and showing the valve connections in the fill and fire settings, respectively, of the actuating knob;

FIG. 7 is a cross-sectional view taken on line 7-7 of FIG. 1;

FIG. 8 is a cross-sectional view through a modified form of the invention;

FIG. 9 is a view taken on line 9'-9 of FIG. 8; and,

FIG. 10 is a pictorial view of the valve assembly of the FIGS. Sand 9 embodiment.

Referring more particularly to the drawings wherein the showings are for the purpose of illustrating preferred embodiments of the invention only and not for the purpose of limiting same, FIG. 1 shows the preferred overall arrangement of an-injector including a controllable volume injection assembly 10, a medicament and actuating fluid supply assembly 12, and an actuating and control valve assembly 14 which serves to regulate flow between assemblies and 12.

It should be appreciated that the assembly A is shown somewhat larger than actual size; however, the specific size and/or configuration of the assembly could vary substantially within the scope of the invention. For this reason, the invention is not to be assumed as limited to the specific details shown.

All of the assemblies l0, l2 and 14 are preferably carried in a common housing or body forming member 16 which can be formed from any suitable material such as aluminum, stainless steel, certain plastics and ceramics. The controllable volume injection assembly 10 is carried within the forward end of the body 16 and includes a cylindrical chamber 18 formed inwardly from the lower surface of body 16. The chamber 18 is formed inwardly from the lower surface of body 16 and, at its inlet end, has enlarged threaded bore portion 20. Positioned within bore 20 is a threaded plug 22 having an outwardly extending threaded sleeve 24. It will be noted that the inner face of plug 22 is provided with a tapered bore 26 which extends inwardly from the inner face in alignment with the axis of chamber 18. Connected to the outwardly extending sleeve 24 is an injection nozzle 28. The chamber and all passageways are formed from material or lined with material to provide a non-wettable surface.

Nozzle 28 can be formed in many different configurations and have outlet orifices of different sizes depending, for example, upon the particular type of injection to be given. In the subject embodiment, the nozzle 28 merely comprises a machined body portion provided with a tapered opening 30 which is aligned with the opening 26 and terminating in an outlet orifice 32. Preferably, the outlet orifice 32 is formed in a nylon bushing 34 which is press-fitted in the nozzle and sealed with an O-ring." This allows a common nozzle body to have many different orifice sizes.

Positioned within the cylindrical chamber 18 is a movable wall means in the form ofa piston member 36 which divides the chamber into a medicament chamber portion 38 and a pressurizing gas chamber portion 40. It should be appreciated that instead of a piston, a fixed diaphragm or the like could, in certain instances, equally well be used. The piston 36 can be formed from any suitable material but is shown as a plastic or polymeric material such I as polyethylene, polypropylene. As is apparent, the piston is mounted for sealed, sliding movement within the cylindrical chamber 18. Its upward limit of movement is adjustably controlled so as to allow the volume of the medicament chamber 38 to be varied as desired. In the embodiment under consideration, adjustment is controlled by a threaded stud member 42. As shown, stud 42 is threaded in an opening 44 formed inwardly from the upper surface of the body 16 in alignment with the chamber 18. By rotating the stud, the upper limit of travel of piston 36 can be varied to thereby vary the quantity of medicament that can be held in chamber As can be appreciated, with medicament in chamber 38, the piston will be movedupward into engagement with the lower end of stud 44. Thereafter, high pressure fluid, preferably gas, can be supplied to chamber portion 40 to drive the piston downwardly to cause the medicament to be expelled at high velocity through orifice 32. The gas pressure is supplied at a level such that the medicament discharged from nozzle 32 has a velocity sufficient to penetrate the patients skin tissue or muscle to the depth desired. It should be understood that the nozzle or orifice size as well as the number of orifices can be varied depending upon the particular type of injection being given and the particular desired end-effect.

Many different types of medicament and gas supply assemblies could be provided; however, in the embodiment shown, a novel, multiple dosage supply assembly 12 is used. The assembly 12 could take many forms but, in the preferred embodiment, comprises a movable housing which can be indexed to bring different gas cartridges and medicament containers or ampules into proper position. The housing comprises a rotatable cylinder 48 having a multiple number of axially extending openings formed therein. The openings and their relationship will be described more fully hereafter but, for present purposes, it is sufficient to note that they are designed to hold small sealed cartridges of high pressure gas and ampules of medicament. The individual ampules are received within the openings and can be connected through the valve assembly 14 with the medicament chamber 38 and the gas chamber 40 by the valve assembly 14. FIG. 4 shows a typical cylindrical-ampule or cartridge of the type which is to be used in the unit.

Referring again to FIGS. 2 and 7, it will be seen that the cylinder 48 has two concentric rows of axially extending openings. An outer row, preferably somewhat larger in diameter than the inner row, has seven openings 50 of uniform diameter adapted to hold pressurizing gas cartridges. The inner row of openings has a plurality of openings, for example seven, each of a uniform first diameter arranged to hold similar medicament ampules which are somewhat larger or smaller than the gas pressure cartridges. Although the openings could be of a uniform size for both gas and medication, the arrangement shown is preferred since it prevents in advertent placing of a gas cartridge within a medicament opening.

The eighth hole in each row is arranged to allow cleaning of the assembly. Opening 54 in the inner row can be utilized for holding a containers or cartridge of cleaning fluid such as buffered physiological salt solution with an added disinfectant or the like. The outer large diameter opening 54 is used for a pressurizing gas cartridge of somewhat larger diameter but lower pressure. The opening 53 is of a larger diameter than the openings 52 so that the cleaning fluid cannot be placed by mistake into a medicament chamber. Further, the use of a larger diameter opening 54 prevents use of a high pressure cartridge so that cleaning fluid cannot be expelled at a velocity sufficient to produce an injection. Although the described variation in chamber openings is preferred for preventing inadvertent injection of cleaning fluid, other methods could be used. For example, different chamber shapes, color coding, etc.

Referring again to FIG. 1, the cylinder 48 is mounted for rotation on a hollow, threaded stud or shaft 56 which is threaded into the body 16. The body 16 has an axially extending circumferential flange portion 58 which surrounds the cylinder 48 while allowing it to be freely rotatable therein. The inner end the cylinder 48 is provided with a cover plate member 60 which is releasably connected to the cylinder by a threaded retainer sleeve 62. The cover plate 60 engages the inner ends of the cartridges and prevents them from moving to the left in the cylinder during an indexing motion which will subsequently be described. Note that the cover plate 60 has openings slightly smaller than the corresponding openings 50, 52, 53 and 54.

In the subject embodiment, means are provided to allow the ampules and cartridges to be punctured and connected in flow relationship with the valve assembly 14. As best shown in FIG. 1, these means comprise hollow needle-like members 62 and 64 carried, respectively, in bores 66 and 68. Needle member 62 is mounted in a threaded member 69 and connects from the valve assembly 14 to the needle end portion 62. Similarly, the needle portion 64 is carried in a threaded member 70. As shown, the inner ends of the cartridges and ampules are punctured as they are moved toward the needles.

In the subject embodiment, the means for controlling rotation and movement of the cylinder 40 comprises a retractable indexing mechanism which includes an outer cup-shaped cover member 72 which is connected to and moves with cylinder 48. Cover member 72 includes an end wall 73 and a sleeve or wall portion 74. The side wall portion 74 closely surrounds the outer circumference of the rearwardly extending sleeve 58 on body 16. The end wall is releasably connected to an internal stud member 76 by screw 75. Stud 76 is slidably received within the outer end of the shaft 56. Note that the stud 76 has a flange portion 78 which is closely received within the center of the shaft 56. A compression spring 80 is positioned between the flange 78 and the inwardly extending flange 81 so as to main tain the stud continually biased to the left to pull the cylinder 48 inwardly. Additionally, it should be noted that a snap-ring 82 is positioned on the outer end of stud 76. Accordingly, the screw 75 can be removed to remove the cup-shaped member 74 and the cylinder for access to the outer ends of the ampule and cartridge holding openings. The snap-ring prevents the stud from sliding within the center of shaft 56.

Proper alignment of cylinder 48 to assure that the sets of gas and medicament cartridges are brought into alignment with the needles 62, 64 is accomplished by'a pin member 84 which is carried on the inner face of end wall 73. Pin 84 is adapted to be received within the openings 86 (see FIG. 7) formed in the end of the sleeve 58. It should be noted that the openings 84 are aligned with the rows of medicament and gas receiving openings of cylinder 48. To index the cylinder 48 to bring a new set of cartridges into alignment with the pins or needles 62, 64, it is only necessary to retract the cup-shaped member 72 to the dotted line position of FIG. 1. At that time, the needle 84 is free of the end of I sleeve 48 and the assembly can be rotated until the pin 84 is in alignment with the next opening 84. The cylinder 48 and the cup-shaped end member 72 can then be pushed to the left causing the new cartridges to be punctured by the needles 62 and 64.

Many different arrangements could be used for controlling the fluid flow of the medicament and high pressure gas from the cylinder 48 to the injection assembly 10; however, the preferred valving arrangement is comprised of a rotary slide valve member 90 which is carried within a bore 92 formed intermediate the sections 10 and 12. The slide valve member 90 is cylindrical and includes a central, somewhat large diameter section 94 and reduced diameters end sections 96 and 98. Suitable passages which will be subsequently described in detail are formed through the central portion 90 to provide connection with the gas and medicament passages. The lower reduced diameter end portion 98 of the valve member is slidably and rotatably received within a plug member 100 threaded into an enlarged diameter bore 102 formed in the lower surface of the body 16. A flange 104 is slidably received within the bore 102 and a compression spring 106 is positioned between the inner face of the threaded member 100 and the flange 104. Flange 104 engages the shoulder between sections 90 and 98 of the valve member. Accordingly, the valve member is normally biased to the upper position shown solid in FIG. 1.

The upper reduced diameter end 96 of valve member 90 is provided with a knob or the like 108 which is releasably connected to portion 96 in any convenient manner such as through the use of a set screw 110. As can be appreciated, the valve 92 can be rotated by knob 108 and, further, by pushing downward on knob 108, the valve can be moved downwardly against the bias of spring 106. This particular arrangement allows various selected passages between the sections 10 and 12 to be connected in desired manners. It should be noted that the lower end of valve member 92 is slotted as shown at 93 in FIGS. 1 and 5. A corresponding fin is carried in plug so that the valve member can be pushed down only when the fin and slot are in alignment, which is in the fire position. Also, positioned under actuating knob 110 is a spring biased detent plunger 111 which engages recesses formed under the knob 110. As the knob is rotated between various positions, the detent plunger provides an indication of proper positioning of the knob.

FIGS. 3, 5, 6A and 63 best illustrate the arrangement of the passages which permits control of the flow of gas and medicament to the injection section l0. As shown, the valve assembly 14 connects the needle 62 with passage 112 to permit medicament to be supplied to the medicament chamber portion 38 of chamber 18. Similarly, the valve controls the supply of pressurizing gas from needle 64 to passage 114 and the connecting which leads to the lower end of the slide valve member 92. Referring to FIG. 1, it will be seen that a corresponding passage 120 is formed through the member 100. Thus, in the solid line position of FIGS. 1 and 5, the gas pressure chamber is connected with atmosphere so as to relieve any internal pressures within the chamber.

The valve member 92 also includes a cross passage 122 which is positioned at a 45 angle relative to passage 117.

To understand the sequence of operations during filling and firing of the injector, reference is again made to FIGS. 3, 5 and 6A and 6B. Assume that the knob 96 is turned so that the indicator arrow 124 is pointing toward the off position. At this time, the slide valve is in its upper solid line position of FIGS. 1 and 5. Accordingly, line 114 is directly connected to atmosphere through line 118 and the cross-connection line 122 is positioned out of alignment with the passage 112. In

this way, no flow can take place from the needles 62 and 64 to the gas or medicament chamber portions when the injector is in the off position. However, when the valve is rotated so that the indicator arrow 124 points to the fill position, passage 122 is in alignment with passages 112 and needle 62. Accordingly, medicament can flow from the medicament capsule into the medicament chamber portion 38. Preferably, and in accordance with one aspect of the invention, the medicament in the capsule is under a slight pressure so as to cause it to be expelled from the capsule to raise the piston 36 into engagement with the lower end of stud 42 thereby filling the chamber. (It should be recalled that by adjustment of the stud 42, the volume of chamber 38 can be varied.) With the medicament chamber properly filled, the valve is then rotated 45 further so that the arrow 124 is pointed at the tire" position. At this time, cross passage 117 is aligned with passage 114 and needle 64; however, it is in the raised solid position shown in FIGS. 1 and 5. Consequently, the gas pressure passage is still in a closed position. When it is desired to release the gas to produce an injection, it is only necessary to push down on knob 108 to bring passage 117 into alignment with needle assembly 64 and passage 114. Thus, as can be seen, one valve assembly controls all filling and firing operations of the unit.

When it is desired to clean the medicament chamber, it is only necessary to index the cylinder 48 to bring the chambers 52 and 54 into-alignment with the needles 62. Thereafter, the same fire and fill operations can be carried out to produce a cleaning of the assembly. Preferably, the gas pressure within the ampule positioned in chamber 54 is substantially less than that required to produce an injection. This eliminates the possibility that cleaning solution could be injected accidentally. It should also be appreciated thatthe outer circumference of the sleeve 74 and 58 can be suitably marked with indicia to indicate the presence of cleaning cartridges in alignment with the needles 62, 64.

Although the particular rotary cylinder arrangement described is preferred, it should be understood that other types of indexable assemblies could be used, for example, slide clip assemblies, multiple barrels or clips, and similar arrangements. Further, although the unit is shown as having seven medicament holding chambers,

it should be understood that other numbers could be provided. The number seven is preferred however, since it allows a weeks supply of medicament to be carried within the unit.

FIGS 8 and 9 illustrate a modified form of the invention which utilizes a substantial different injector assembly and which can use the same type of indexable supply chamber if desired; however, it is shown with a simple supply section which holds only one medicament ampule and one gas pressure ampule. in particular, the embodiment of FIGS. 8 and 9 comprises a generally rectangular body formed from any suitable material, either metal, plastic, or ceramic. The body has a relatively large diameter, centrally located cylindrical bore 152 which extends inwardly from the lower face substantially through the body but leaving a small flange portion 154'. Positioned within the bore 152 is a slidable, cylindrical housing member 156 which is closely and slidably received within bore 152. Additionally, a key member (not shown) prevents rotation of member 156 Member 156 is prevented from moving out the lower end of the bore by a retainer ring 158 threaded in the lower end of bore 152. The body member 156 is normally maintained biased in engagement with retainer 158 by a relatively light compression spring 160 positioned between shoulder 162 and flange 154.

Formed axially within member 156 is an internal bore 164 which constitutes the medicament and gas pressure chambers. The lower end of bore 164 is provided with a small diameter outlet 166 which connects with the nozzle outlet orifice 168. As shown, the nozzle member 170 is releasably threaded to the end of body 156 so that it can be changed as desired.

Positioned within the bore 164 and dividing it into a pressurized gas chamber portion 172 and a medicament chamber portion 174 is a piston 176. Piston 176 is formed from any suitable material so as to provide a proper seal between the two chamber portions while allowing relatively free movement of the piston vertically in the chamber.

In this embodiment, adjustment of the medicament quantity is controlled by a threaded sleeve member 178 carried in the upper end of bore 164. By rotation of member 178, its lower end 180 is shifted so as to vary the maximum vertical upward distance that the piston 176 can move. This, of course, varies the space or size of the medicament chamber 174. Adjustment of the member 178 is indicated, for example, by suitable indicator marks formed on the body 150 and the upper surface of member 178.

In the subject embodiment, means are provided for selectively moving the piston 176 to its upper position so that filling of the medicament chamber portion can take place. These means comprise a vertically reciprocable shaft 182 having an enlarged lower end portion 184. The shaft 182 is connected at its upper end with a push button or actuating knob 184 having an outwardly extending flange sealing surface 186. Note that the flange portion 186 engages under a machined flange or lip 188 formed internally of member 178. This seals the pressure chamber. Additionally, a biasing spring 190 acts against the under surface of push button 178 to maintain the shaft and push button normally biased to the solid line position. At is lower end, the

spring 190 engages a snap ring 192 positioned in an internal groove in member 178.

To raise the piston 176 to its upper position, push button 184 is pushed downwardly driving the enlarged diameter end portion 184 into a correspondingly shaped opening 194 formed in piston 176. Thereafter, release of the push button allows the spring 190 to push the shaft and push button back to the solid line position shown. This pulls the piston 178 upwardly into engagement with the end face 180. Additionally, portion 184 retracts from opening 194 and the piston stays in its raised position merely by friction between the piston and the internal walls or bore 164. With the piston in the raised position, medicament can be supplied to the medicament chamber 174.

In the subject embodiment, the medicament ampules and gas cartridges 198, 199 are carried in suitable bores formed inwardly from the right hand end of body 154. Note that a cover plate 204 is connected to the body with a screw 206. By removing screw 206, cover plate 204 can be removed and the used cartridges removed and new cartridges placed therein. Additionally, suitable needles for puncturing the ends of the sealed cartridges are carried on the inner ends of the bore in the manner shown in FIG. 8.

The medicament is supplied from medicament ampule 198 through the valve assembly 200 to line 202 which connects through passage 166 with medicament chamber 174. Preferably, the medicament ampule is under a slight internal pressure so that medicament is forcibly actuated into the chamber 174. However, although the medicament ampule is shown as having a different configuration than that used in the FIG. 1 embodiment, it should be appreciated that the same medicament ampules could be used, if desired.

The valve assembly 200 comprises a cylindrical valve member 210 closely received within a cylindrical bore 212 formed inwardly from the upper surface of body 150. The valve member 210 is retained in the bore while being free to rotate by a retainer plate member 214 which is positioned in a groove 216 which extends across the top surface of body 150. A flange 218 is formed about valve member 210 and is held beneath the plate 214.

Valve member 210 is provided with transversely extending passages which function to connect the gas and medicament supply passage with the chambers. At the lower end of the valve member 210, passage 218 is positioned so that when the valve member is rotated to the fill" position shown in FIG. 9, passage 218 connects from the needle 220 to the passage 202. At this time, the upper transverse passage 222 is out of alignment with the gas supply needle 224 so that the apparatus cannot be inadvertently fired.

After the medicament chamber 174 has been filled, the valve member 210 can be rotated back to the fire" position. Consequently, transverse passage 222 is aligned with needle 224 and passage 226. it is still not possible however, to supply high pressure gas to the gas chamber 172. Note that the connecting passage 228 is formed from the gas chamber 172 through the wall of member 156 as best shown in FIG. 8. Although passage 228 is in vertical alignment with passage 226, in the normal position of member 156 it is substantially therebelow. Accordingly, engagement of member 256 and the internal wall of bore 152 serves as a valve to prevent flow of gas into the gas pressure chamber. When it is desired to inject the medicament, it is only necessary to press the nozzle against the patients skin and move member 156 upwardly against the bias of spring 160. When passage 228 is aligned with passage 226, high pressure gas can flow into the chamber to product an injection.

Various modifications of the components of the described unit can, of course, be made. For example, rather than use a rotary valve as shown, various types of snap acting or slide valves could be used. Further, although not shown, different types of O-ring seals and the like could be utilized to provide sealing between the various surfaces.

Cleaning of the subject embodiment could be accomplished in the manner described with reference to the FIGS. 1 through 9 embodiments, i.e., a pressurized cleaning fluid ampule could be placed in the chamber for the medicament ampule 198 and the unit filled and fired. However, the subject embodiment provides an arrangement whereby the passage 230 can be used to flush cleaning fluid through the medicament chamber 174 as well as through the medicament ampule and the needle 220. Note that a second needle 232 is connected into the medicament ampule 198. A flow passage 234 connects from needle 232 to the bore 212. Valve member 210 has a transversely extending passage 236 which, when the valve is rotated to the clean position, connects between lines 230 and 234. Also, a laterally extending cross passage 238 is, when the device is in the cleaning position, connected between lines 202 and needle 220. Consequently,

cleaning fluid can be flushed with a syringe through line 230 and needle 232 back through needle 220 to chamber 174.

Many other modifications of the device can be made. For example, the nozzles 28 and can be color coded with the medicament and gas pressure ampules for various types of injections. For example, for intramuscular injections, a higher gas pressure may be used together with a nozzle of a particular diameter. ln such instances, the proper nozzle can be made of the same color as the gas pressure cartridge. These and similar modifications are within the scope of the invention as set forth in the appended claims.

What is claimed is:

1. A velocity type medicament injector comprising:

a first body portion including a medicament receiving chamber having at least one orifice through which medicament can be ejected, said chamber including at least one movable wall portion through which pressure can be applied to medicament in said chamber to cause it to be ejected through the orifice at a velocity sufficient to enter tissue without use of a needle;

a second body portion connected with said first body portion and including housing means carrying a plurality of fluid containers and at least one propellant gas cartridge;

passage means including valve means connected between the housing means and the first body portion to controllably supply fluid and pressurizing gas to the chamber on opposite sides of the movable wall; and,

indexing means for permitting movement of at least that portion of the housing means which carries said plurality of fluid containers relative to the first body portion to bring selected ones of said fluid containers into flow relationship with said passage means.

2. The injector as defined in claim 1 wherein said housing means is mounted for rotation about a fixed axis.

3. The injector as defined in claim 1 wherein at least one of said containers contains a cleaning solution which can be indexed into alignment with the passage means for cleaning at least the medicament receiving chamber.

4. The injector as defined in claim 1 wherein said orifice includes means for permitting its diameter and number of orifices as well as length to be varied.

5. The injector as defined in claim 1 wherein said movable wall comprises a piston slidable in said medicament chamber and dividing said medicament chamber into first and second chamber portions.

6. The injector as defined in claim 1 wherein said valve means is carried in said first body portion and comprises a rotatable valve member.

7. The injector as defined in claim 1 wherein said movable wall means comprises a piston in said medicament chamber and wherein said passage means includes a first passage for supplying pressurized gas to one side of said piston and a second passage for supplying medicament to the opposite side of said piston.

8. The injector as defined in claim 1 wherein said medicament chamber includes means for adjusting the amount of medicament which can be held in said chamber.

9. The injector as defined in claim 1 wherein the means for adjusting the amount of medicament comprises means for limiting movement of said movable wall portion.

10. The injector as defined in claim 1 wherein said carrier is mounted for rotation about an axis and longitudinal movement along said axis.

11. The injector as defined in claim 1 wherein said housing means includes openings in which said containers are received, said openings including means for opening said containers.

12. The injector as defined in claim 1 wherein said movable wall includes a piston slidable in said medicament chamber and including means for limiting the movement of said piston.

13. The injector as defined in claim 1 wherein said housing means includes means for indicating the number of unused containers carried therein.

14. The injector as defined in claim 1 wherein said orifice is defined by a removable end wall on said chamber.

15. The injector as described in claim 7 wherein said valve means comprises a single valve element controlling flow through between said first and said second passage portions.

16. The injector as described in claim 7 wherein means are provided for bleeding gas from said medicament chamber.

17. A velocity type medicament injector including a first housing adapted to hold medicament and a propela second housing carried by said first housing and movable relative thereto, said second housing including a medicament chamber having a movable wall portion and an outlet orifice through which medicament can be ejected; passageway means for supplying medicament from said first housing to said medicament chamber, said passageway means further including a gas passageway extending through the second housing for supplying pressurized gas from said first housing to a position behind the movable wall portion; and,

means associated with said second housing to prevent gas from flowing through said gas passageway except upon movement of the second housing relative to the first housing in a direction toward the outlet orifice.

18. The injector as defined in claim 17 wherein said second housing is carried in said first housing and is slidable relative thereto.

19. The injector as defined in claim 17 wherein said second housing is slidable in said first housing and wherein said means to prevent pressurizing gas from flowing through the passageway comprises cooperating valve surfaces formed in said first and said second housing portions.

20. The injector as defined in claim 17 including biasing means for continually biasing said second housing to a position wherein gas is prevented from flowing through said passageway.

21. The injector as defined in claim 17 wherein said medicament chamber includes means for adjusting the amount of medicament which can be held in said chamber.

22. The injector as defined in claim 17 wherein said movable wall means includes means for selectively moving it to desired positions. 

1. A velocity type medicament injector comprising: a first body portion including a medicament receiving chamber having at least one orifice through which medicament can be ejected, said chamber including at least one movable wall portion through which pressure can be applied to medicament in said chamber to cause it to be ejected through the orifice at a velocity sufficient to enter tissue without use of a needle; a second body portion connected with said first body portion and including housing means carrying a plurality of fluid containers and at least one propellant gas cartridge; passage means including valve means connected between the housing means and the first body portion to controllably supply fluid and pressurizing gas to the chamber on opposite sides of the movable wall; and, indexing means for permitting movement of at least that portion of the housing means which carries said plurality of fluid containers relative to the first body portion to bring selected ones of said fluid containers into flow relationship with said passage means.
 1. A velocity type medicament injector comprising: a first body portion including a medicament receiving chamber having at least one orifice through which medicament can be ejected, said chamber including at least one movable wall portion through which pressure can be applied to medicament in said chamber to cause it to be ejected through the orifice at a velocity sufficient to enter tissue without use of a needle; a second body portion connected with said first body portion and including housing means carrying a plurality of fluid containers and at least one propellant gas cartridge; passage means including valve means connected between the housing means and the first body portion to controllably supply fluid and pressurizing gas to the chamber on opposite sides of the movable wall; and, indexing means for permitting movement of at least that portion of the housing means which carries said plurality of fluid containers relative to the first body portion to bring selected ones of said fluid containers into flow relationship with said passage means.
 2. The injector as defined in claim 1 wherein said housing means is mounted for rotation about a fixed axis.
 3. The injector as defined in claim 1 wherein at least one of said containers contains a cleaning solution which can be indexed into alignment with the passage means for cleaning at least the medicament receiving chamber.
 4. The injector as defined in claim 1 wherein said orifice includes means for permitting its diameter and number of orifices as well as length to be varied.
 5. The injector as defined in claim 1 wherein said movable wall comprises a piston slidable in said medicament chamber and dividing said medicament chamber into first and second chamber portions.
 6. The injector as defined in claim 1 wherein said valve means is carried in Said first body portion and comprises a rotatable valve member.
 7. The injector as defined in claim 1 wherein said movable wall means comprises a piston in said medicament chamber and wherein said passage means includes a first passage for supplying pressurized gas to one side of said piston and a second passage for supplying medicament to the opposite side of said piston.
 8. The injector as defined in claim 1 wherein said medicament chamber includes means for adjusting the amount of medicament which can be held in said chamber.
 9. The injector as defined in claim 1 wherein the means for adjusting the amount of medicament comprises means for limiting movement of said movable wall portion.
 10. The injector as defined in claim 1 wherein said carrier is mounted for rotation about an axis and longitudinal movement along said axis.
 11. The injector as defined in claim 1 wherein said housing means includes openings in which said containers are received, said openings including means for opening said containers.
 12. The injector as defined in claim 1 wherein said movable wall includes a piston slidable in said medicament chamber and including means for limiting the movement of said piston.
 13. The injector as defined in claim 1 wherein said housing means includes means for indicating the number of unused containers carried therein.
 14. The injector as defined in claim 1 wherein said orifice is defined by a removable end wall on said chamber.
 15. The injector as described in claim 7 wherein said valve means comprises a single valve element controlling flow through between said first and said second passage portions.
 16. The injector as described in claim 7 wherein means are provided for bleeding gas from said medicament chamber.
 17. A velocity type medicament injector including a first housing adapted to hold medicament and a propellant gas; a second housing carried by said first housing and movable relative thereto, said second housing including a medicament chamber having a movable wall portion and an outlet orifice through which medicament can be ejected; passageway means for supplying medicament from said first housing to said medicament chamber, said passageway means further including a gas passageway extending through the second housing for supplying pressurized gas from said first housing to a position behind the movable wall portion; and, means associated with said second housing to prevent gas from flowing through said gas passageway except upon movement of the second housing relative to the first housing in a direction toward the outlet orifice.
 18. The injector as defined in claim 17 wherein said second housing is carried in said first housing and is slidable relative thereto.
 19. The injector as defined in claim 17 wherein said second housing is slidable in said first housing and wherein said means to prevent pressurizing gas from flowing through the passageway comprises cooperating valve surfaces formed in said first and said second housing portions.
 20. The injector as defined in claim 17 including biasing means for continually biasing said second housing to a position wherein gas is prevented from flowing through said passageway.
 21. The injector as defined in claim 17 wherein said medicament chamber includes means for adjusting the amount of medicament which can be held in said chamber. 